Photovoltaic cell and its transparent light conversion powder

Abstract

A photovoltaic cell is disclosed to include a monocrystalline silicon wafer, and a transparent light conversion powder which is made in the form of a polymer layer with a transparent phosphor powder filled therein and kept in contact with the outer surface of the monocrystalline silicon wafer to enhance the absorption of the short-wavelength radiation ultraviolet λ<480 nm of the sun and to re-radiate in the wavelength range λ=500˜980 nm, wherein the phosphor powder is formulated as Me II O.xB 2 O 3 :EuCePrTbLi, in which Me II =(Mg +2 ,Ca +2 ,Sr +2 ,Ba +2 ), 0.1<x<10, preferably in the range of 0.5<x<2. Furthermore, the invention also provides a transparent light conversion powder for photovoltaic cells.

1 . A photovoltaic cell, comprising:
 a monocrystalline silicon wafer; and   a transparent light conversion layer made in the form of a polymer layer with a transparent phosphor powder filled therein and kept in contact with an outer surface of said monocrystalline silicon wafer to enhance the absorption of the short-wavelength radiation ultraviolet λ<480 nm of the sun and to re-radiate in the wavelength range λ=500˜980 nm, said phosphor powder being formulated as Me II O.xB 2 O 3 :EuCePrTbLi, in which Me II =(Mg +2 ,Ca +2 , Sr +2 ,Ba +2 ).   
     
     
         2 . The photovoltaic cell as claimed in  claim 1 , wherein said monocrystalline silicon wafer is a p-type monocrystalline silicon wafer, a p-type polycrystalline silicon wafer, an n-type monocrystalline silicon wafer, or an n-type polycrystalline silicon wafer; said transparent phosphor powder is a super-dispersion phosphor particle; said transparent light conversion layer is an oxygen-containing polymer with polycarbonate, and/or polysiloxanes, and/or acrylatepolymer as its substrate, and the polymer has a high transmittance in a wide range of wavelength λ=400˜1200 nm and its addition percentage is 0.1˜50% wt. 
     
     
         3 . The photovoltaic cell as claimed in  claim 1 , wherein said transparent light conversion layer has filled therein epoxy resin. 
     
     
         4 . The photovoltaic cell as claimed in  claim 1 , wherein said transparent phosphor powder has added thereto Eu, Ce, Pr, Tb and Li., and the addition of Eu is 0.1˜15%; Ce is 0˜15%; Pr is 0˜1%; Tb is 0˜1%, and Li is 0.1˜30% by molecule percentage. 
     
     
         5 . A photovoltaic cell, comprising:
 a monocrystalline silicon wafer; and   a transparent light conversion layer made fusing a transparent phosphor powder with a glass material, and bonded to an outer surface of said monocrystalline silicon wafer to enhance the absorption of a first specific wavelength range of the sun and to re-radiate in a second specific wavelength range, said phosphor powder being formulated as Me II O.xB 2 O 3 :EuCePrTbLi, in which Me II =(Mg +2 ,Ca +2 , Sr +2 ,Ba +2 ).   
     
     
         6 . The photovoltaic cell as claimed in  claim 5 , wherein said monocrystalline silicon wafer is a p-type monocrystalline silicon wafer, a p-type polycrystalline silicon wafer, an n-type monocrystalline silicon wafer, or an n-type polycrystalline silicon wafer; said first specific wavelength range is λ=480 nm; said second specific wavelength range is λ=500˜980 nm. 
     
     
         7 . The photovoltaic cell as claimed in  claim 5 , wherein said transparent phosphor powder is a super-dispersion phosphor particle, having added thereto Eu, Ce, Pr, Tb and Li., and the addition of Eu is 0.1˜15%; Ce is 0˜15%; Pr is 0˜1%; Tb is 0˜1%, and Li is 0.1˜30% by molecule percentage. 
     
     
         8 . The photovoltaic cell as claimed in  claim 5 , wherein said transparent phosphor powder and said glass material have a common melting point about 1000° C., and the ratio of said transparent phosphor powder in said transparent light conversion layer is 0.1˜75% wt. 
     
     
         9 . A photovoltaic cell, comprising:
 a monocrystalline silicon wafer;   a glass placed on an outer surface of said monocrystalline silicon wafer; and   a transparent thin layer bonded to a back side of said glass and kept in contact with the outer surface of said monocrystalline silicon wafer to enhance the absorption of the radiation of the sun in a first specific wavelength range and to re-radiate in a second specific wavelength range, said phosphor powder being formulated as Me II O.xB 2 O 3 :EuCePrTbLi, in which Me II =(Mg +2 ,Ca +2 , Sr +2 ,Ba +2 ).   
     
     
         10 . The photovoltaic cell as claimed in  claim 9 , wherein said monocrystalline silicon wafer is a p-type monocrystalline silicon wafer, a p-type polycrystalline silicon wafer, an n-type monocrystalline silicon wafer, or an n-type polycrystalline silicon wafer; said first specific wavelength range is λ=480 nm; said second specific wavelength range is λ=500˜980 nm; said transparent thin layer has a thickness about 2 mm and a transmittance >85%. 
     
     
         11 . The photovoltaic cell as claimed in  claim 9 , wherein said transparent phosphor powder is a super-dispersion phosphor particle, having added thereto Eu, Ce, Pr, Tb and Li., and the addition of Eu is 0.1˜15%; Ce is 0˜15%; Pr is 0˜1%; Tb is 0˜1%, and Li is 0.1˜30% by molecule percentage. 
     
     
         12 . A transparent phosphor powder being to enhance the absorption of the short-wavelength radiation λ<480 nm of the sun and to re-radiate in the wavelength range λ=500˜980 nm, for the photovoltaic cell assembly and in turn form more separate p-n electron-hole pairs, said phosphor powder being formulated as Me II O.xB 2 O 3 :EuCePrTbLi, in which Me II =(Mg +2 ,Ca +2 , Sr +2 ,Ba +2 ). 
     
     
         13 . The transparent phosphor powder as claimed in  claim 12 , which has added thereto Eu, Ce, Pr, Tb and Li., and the addition of Eu is 0.1˜15%; Ce is 0˜15%; Pr is 0˜1%; Tb is 0˜1%, and Li is 0.1˜30% by molecule percentage.